1. Field of Art of the Invention
This invention relates to an improved system for automatically maintaining a boat at or very near a speed set by the operator, particularly when the boat is pulling a water skier.
2. Description of the Related Art
An automatic speed control system for boats is described in the patent application of Ser. No. 07/546394, now U.S. Pat. No. 5,074,810. This system maintains the speed of a boat at a value set by the operator by measuring boat speed, comparing this measured speed to the desired speed, and adjusting the throttle of the engine to minimize the difference between the measured speed and the desired speed. For the application of competitive water skiing, however, this system does not always respond quickly enough to compensate for the sudden change in load due to maneuvers by the skier, and therefore cannot always prevent noticeable changes in boat speed resulting from these loads. Additionally, this system can perform erroneously if debris in the water clogs, or partially clogs the Pitot tube used to measure boat speed.